Suture anchors are commonly employed during surgical procedures to secure soft tissue to bone. Such anchors are generally inserted into a pre-formed hole in the bone, so that a portion of filamentary material (e.g., suture material) extends out of the hole from the anchor. Suture material, as the term is used and described herein, include monofilament or multi-filament suture as well as any other metallic or non-metallic filamentary or wire-like material suitable for performing the function of a suture. This material can include both absorbable and non-absorbable materials.
For open and closed surgical procedures, the suture material is tied to the soft tissue in a manner that forms a knot. But for surgical procedures that are typically closed, including those procedures performed arthroscopically or endoscopically, the knot is often difficult to form. Suture anchors that do not require a knot, also referred to as “knotless suture anchors,” have been developed to avoid the step of tying the knot.
One example of a knotless suture anchor is shown in U.S. Pat. No. 6,692,516 to West Jr. et al., assigned to the assignee hereof and incorporated by reference in its entirety herein. There is provided here an expandable metallic knotless suture anchor, which is difficult to implement in the form of non-metallic material. Another example is shown in U.S. Patent Application Publication No. 2005/0055052 filed by Lombardo et al., and assigned to the assignee hereof and incorporated by reference in its entirety herein. This application discloses a knotless suture anchor that is constructed of bioabsorbable material, but may be limited in its application to certain surgical procedures.
This limitation to certain surgical procedures is unfortunate because other procedures, including rotator cuff repairs, would benefit from knotless suture anchors, and more particularly, from a knotless suture anchor that is secured to the cancellous bone. It would be likewise beneficial if the knotless suture anchor is provided so as to prevent the tendency to migrate above the cortical layer of the bone, as well as from the level of the humeral head or other bone at the anchor site.
Therefore, there is a need for a knotless suture anchor that is compatible with a wide range of surgical procedures. There is likewise a need that the proposed knotless suture anchor is configured to engage not only the cancellous bone, but also to engage the bone in a manner that prevents migration of the anchoring device.